Head fire rings

[Scooby d]

I will post some pics of gasket when I figure out how Lol .checked liner heights and they are all at 9 thousandths but they are all very level. Can I get a 6 or 7 thousandths shim or what are my shim options?

[Scooby d]

And I wanted to add that the liners were not clamped down at nine thousanths.

[Rawze]

(05-23-2022 )Scooby d Wrote:  And I wanted to add that the liners were not clamped down at nine thousanths.

They are supposed to be clamped with 100 ft.lbs of force on each side to measure their height. Also, even if you do this, a dropped liner does not always show up by checking them like that. It is unreliable.

Also... if the enigne comes apart after 400+k miles or more.. and you do not counter-bore it then you will not extend its life by one damn bit. it must be counter-bored and liners raised to 0.015" to get it to last a long time again.

here are the depths to cut the block to...
ref: http://rawze.com/forums/showthread.php?t...9#pid28349

[Scooby d]

Thank you rawze for the reply .. yes I was just meaning by my post that I know now that I will have to counter bore and shim my liners. I just measured them like they were to see if they were even close and they are not . You had mentioned earlier that they need to be like 14/15 thousands so I plan to do that. I will torque them all and measure them later to see exactly were they are. i was just saying they were all to low even before clamping them down so I know that I'm looking at a counter bore job. What will my options be for shim thicknesses? Also my #6 liner looks strange. the hash marks in the top 2/3 inches of the liner are almost gone so my theory is that its been leaking and rusting for a while. I'll be pulling it out and replacing it and the rings.there is a definite line were the pison stops every time and the hash marks look great below that line. If I find any electrolysis I'm just going to pull them all. I'm so far in now that I may as well do it all to the best of my ability..Lol

[Rawze]

(05-24-2022 )Scooby d Wrote:  Thank you rawze for the reply .. yes I was just meaning by my post that I know now that I will have to counter bore and shim my liners. I just measured them like they were to see if they were even close and they are not . You had mentioned earlier that they need to be like 14/15 thousands so I plan to do that. I will torque them all and measure them later to see exactly were they are. i was just saying they were all to low even before clamping them down so I know that I'm looking at a counter bore job. What will my options be for shim thicknesses? Also my #6 liner looks strange. the hash marks in the top 2/3 inches of the liner are almost gone so my theory is that its been leaking and rusting for a while. I'll be pulling it out and replacing it and the rings.there is a definite line were the pison stops every time and the hash marks look great below that line. If I find any electrolysis I'm just going to pull them all. I'm so far in now that I may as well do it all to the best of my ability..Lol

Cummins makes standard 0.020" hardened brass shimms or 0.032" shimms for raising the liners. The link above shows the depths to cut the block to get the liners back to 0.015" for each of these shims. - The first time the block is counter-bored, the 0.020" shims are the ones to use.

"... An OEM shim of 0.020" and a depth of 4.740" results in 0.015" height. <- OPTIMAL HEIGHT!. ..."

[Scooby d]

Checked liner #6 yesterday and compressed it measures 5 thousands on exhaust side so ill be pulling all liners and ordering the Monaco 50145 today.

[DVT873]

(05-21-2022 )Rawze Wrote:  

(05-21-2022 )FnG92 Wrote:  What's the heaviest weight you think 3.55 rear could pull safely or with minimal wear? (Isx15 2350 450 hp stock mandated above 80k with 10 spd)

3.55's are in the taller range for even 80k gross weights... so the answer would be in fact 80k.

==================
here are the numbers for 22.5 low-pro tires ....

On the lowest rpm, no load ...


Optimal RPM When pulling hills, mountains, etc...


Sustained top end speed ...

Tags:

eaton rear ratio charts, eaton axle ratios, rear ratios, rear end ratios, rear end charts, rear ratio vs weights, weights vs ratios

(continued on next post)...

Rawze
Probably a dumb question. When ratio's are being discussed I do not see trans final ratios mentioned. I have always thought that final ratio was trans ratio x rear axle ratio. If rears are 3.54 final will vary if trans is a .82 OD vs Direct. What am I missing. In calculating road speeds many times over the years I know the trans ratio has to be part of the calculation just like RPM and tire size.

[Rawze]

(05-29-2022 )DVT873 Wrote:  ...
Probably a dumb question. When ratio's are being discussed I do not see trans final ratios mentioned. I have always thought that final ratio was trans ratio x rear axle ratio. If rears are 3.54 final will vary if trans is a .82 OD vs Direct. What am I missing. In calculating road speeds many times over the years I know the trans ratio has to be part of the calculation just like RPM and tire size.

Because the bulk of truck trannies are always 0.73 over in their top gear. I know that some are not.. but the general discussion is usually around that top ratio.

Also, it is due to the fact that the top gear, being 1.0 or 0.86, 0r 0.73 is mostly irrelevant when looking at engine longevity vs rear end ratios. This is because when the engine is working its hardest, like climbing hills, inclines, accelerating from traffic lights over and over, etc... it is NOT that top gear that is the concern, but all of the lower gears vs. the rear end ratio. Making the engine work harder in every single gear due to taller the rear ends is what eats the engine up the most.

Bettering the rear end ratio and letting the engine use higher rpm is the solution to a longer lasting engine no matter what tranny you have, simply because the entire gear train and engine does not have to produce as much torque to get the truck moving at the same rate. Torque is the enemy of wear. Less torque and more rpm to produce the same amount of work from the engine = longer engine life.. no matter what gear or range you are in.

I have driven trucks with directs in them and 2.27' or 3.08's and they will not get out of their own damn way when loaded compared to a truck with a set of 4.11's in it. This even when only usng the lowest gears ... because the engine has to work a whole heck of a lot harder to overcome those tall rears in every single gear and range .. not just the couple gears at the top end that are different.

[DVT873]

Interesting. My exposure was all medium duty, max gross was usually maybe 60k. By the mid 90's almost everything had gone auto, mostly Allison. Did get into some issues with wide vs close ratio. Fall on their face between 3rd and 4th with wide ratio. Taller gear as in 5.57 vs 4.56 gave better launch and stronger pulling thru the midrange. Have never quite got my head wrapped around "torque converter effect" but it is a factor. Above 30K usually is a 3000 series. 2000,3000 and 4000 all lock-up.
Thanks